Window channels are commonly employed to mate glass to a window frame.
These window channels typically comprise soft, resilient materials that provide structural integrity and often advantageously provide an environmental or acoustical seal. As a result, many window channels are referred to as weatherseals. In certain uses, such as in automobiles and the like, the weatherseal also provides a surface against which a retractable window can slide and seal. In addition to providing an adequate seal, it is desirable that the weatherseal is abrasion resistant and demonstrates a low coefficient of friction.
In one instance, window channels may be enhanced with a slip coat that may include a polymeric film or layer that is applied over a substrate layer, which is typically a rubbery material. For example, U.S. Pat. No. 5,447,671 describes a weatherseal that includes a contacting layer applied to a substrate. The substrate comprises a resilient and flexible synthetic resin or synthetic rubber, and the contacting layer may include a blend of high molecular weight polyethylene (300,000 g/mol) and ultra-high molecular weight polyethylene (1,300,000 g/mol).
U.S. Pat. No. 6,146,739 describes a glass-run channel that includes a contact part that includes a substrate layer and a slide-resin layer. The substrate layer includes a thermoplastic elastomer (e.g., a blend of a rubber and thermoplastic resin), and the slide-resin layer includes an ultra-high molecular weight polyolefin having an intrinsic viscosity of 7 to 40 dl/g as measured in a solvent at 135° C. decalin, a polyolefin having an intrinsic viscosity of 0.1 to 5 dl/g as measured in a solvent at 135° C. decalin, and a thermoplastic elastomer that includes a rubber and a thermoplastic resin.
JP Kokai 7-346094 describes slip-coat compositions that contain fully or partially-crosslinked olefin-based thermoplastic elastomer, a thermoplastic polyolefin resin, a plasticizer, and a filler, with a fatty amide, and either a polyolefin resin or an organopolysiloxane or both a polyolefin resin and an organopolysiloxane, and optionally silica. Exemplified are organopolysiloxanes characterized as ultra-high molecular weight silicon oil sold under the tradename BY16-140 (Dow Corning Toray Silicone Co. Ltd.) or silicone having 1,000,000 cSt viscosity sold under the tradename SH200 (Dow Corning Toray Silicon Co. Ltd.).
There remains a need to improve weatherseals and particularly the slip coatings of the weatherseals. In particular, there remains a need to improve the coefficient of friction of these slip coatings as well as the surface characteristics of these coatings, such as their appearance.